Figure 2.

A) Tibia length was calculated ([3-dimensional motion analysis/measured [clinic-based]) as the distance between knee joint center and ankle joint center (Z₂− Z₁). B) Example of initial measure of frontal plane knee alignment and frontal plane knee alignment taken at maximum knee flexion during landing. The calibrated displacement measure between the 2 marked knee alignments (X₂− X₁) is representative of knee valgus motion during the drop-vertical jump. C) Example of initial measure of sagittal plane knee flexion (Θ₁) and knee flexion angle taken at maximum knee flexion (Θ₂) during landing. The displacement of knee flexion is found by calculating the differences in knee flexion position (Θ₁₋Θ₂).